1. Field of the Invention
This invention relates to a method of making a composition for coating glass, to a composition for coating glass, to a method of coating glass and to a coated glass item.
2. Description of the Related Art
Prior art coatings known to the applicant include UV-curable acrylate coatings, siloxane coatings, single and multiple polyurethane coatings, epoxy coatings and acrylate coatings. Prior art coatings which have a strengthening effect include polyacrylate coatings as disclosed in U.S. Pat. No. 4,891,241 and siloxane coatings as disclosed in U.S. Pat. No. 6,013,333 and U.S. Pat. No. 5,567,235. The polyacrylate coatings required ultraviolet curing whereas the siloxane coatings were found to be susceptible to a loss of strength in humid environments. The polyurethane coatings of U.S. Pat. No. 4,093,758, U.S. Pat. No. 4,053,076, EP 025992 and U.S. Pat. No. 5,837,795 were used mainly for anti-scattering or anti-shattering coatings for bottles. These coatings were also used as protective coatings to retain the initial strength of the bottle. Anti-caustic and abrasion resistant polymeric coatings for bottles are disclosed in U.S. Pat. No. 4,056,208 and a three layer coating consisting of a silane primer, an epoxy layer and an acrylate layer is disclosed in JP 2002347769 A and JP 2002059932A.